Particularly in nasal sinus surgery, positioning of instruments during the surgery is critical due to the proximity of the sinuses to sensitive features such as the brain and the optic nerves. Various methods are known in the patent literature for facilitating positioning of such instruments.
For example, U.S. Patent Application 2012/0265094, to Goldfarb et al., whose disclosure is incorporated herein by reference, describes a method that is useable to facilitate transnasal insertion and positioning of a guidewire. The method involves direct viewing of the guidewire via an endoscope.
U.S. Patent Application 2012/0078118, to Jenkins et al., whose disclosure is incorporated herein by reference, describes an illuminating guidewire device. The disclosure states that the device may be employed to provide trans-illumination, and may facilitate visualization of target anatomy.
U.S. Pat. No. 6,246,231, to Ashe, whose disclosure is incorporated herein by reference, describes a magnetic field position and orientation measurement system. The system is stated to contain, confine and re-direct the magnetic field from one or more transmitters such that the fields are attenuated in areas outside of the operating volume in areas where metallic objects are commonly found.
Documents incorporated by reference in the present patent application are to be considered an integral part of the application except that, to the extent that any terms are defined in these incorporated documents in a manner that conflicts with definitions made explicitly or implicitly in the present specification, only the definitions in the present specification should be considered.